diff --git a/mozilla/accessible/src/base/nsAccessNode.cpp b/mozilla/accessible/src/base/nsAccessNode.cpp
index 42d81c69a8d..c409a4639a3 100755
--- a/mozilla/accessible/src/base/nsAccessNode.cpp
+++ b/mozilla/accessible/src/base/nsAccessNode.cpp
@@ -64,6 +64,7 @@
 #include "nsIStringBundle.h"
 #include "nsITimer.h"
 #include "nsRootAccessible.h"
+#include "nsIFocusController.h"
 
 /* For documentation of the accessibility architecture, 
  * see http://lxr.mozilla.org/seamonkey/source/accessible/accessible-docs.html
@@ -664,4 +665,37 @@ void nsAccessNode::ClearCache(nsInterfaceHashtable<nsVoidHashKey, nsIAccessNode>
   aCache.Enumerate(ClearCacheEntry, nsnull);
 }
 
+already_AddRefed<nsIDOMNode> nsAccessNode::GetCurrentFocus()
+{
+  nsCOMPtr<nsIPresShell> shell = GetPresShellFor(mDOMNode);
+  NS_ENSURE_TRUE(shell, nsnull);
+  nsCOMPtr<nsIDocument> doc = shell->GetDocument();
+  NS_ENSURE_TRUE(doc, nsnull);
 
+  nsCOMPtr<nsPIDOMWindow> privateDOMWindow(do_QueryInterface(doc->GetWindow()));
+  if (!privateDOMWindow) {
+    return nsnull;
+  }
+  nsIFocusController *focusController = privateDOMWindow->GetRootFocusController();
+  if (!focusController) {
+    return nsnull;
+  }
+  nsCOMPtr<nsIDOMElement> focusedElement;
+  focusController->GetFocusedElement(getter_AddRefs(focusedElement));
+  if (!focusedElement) {
+    return nsnull;
+  }
+  nsIDOMNode *focusedNode;
+  focusedElement->QueryInterface(NS_GET_IID(nsIDOMNode), (void**)&focusedNode);
+  if (!focusedNode) {
+    // Document itself may have focus
+    nsCOMPtr<nsIDOMWindowInternal> focusedWinInternal;
+    focusController->GetFocusedWindow(getter_AddRefs(focusedWinInternal));
+    if (focusedWinInternal) {
+      nsCOMPtr<nsIDOMDocument> focusedDOMDocument;
+      focusedWinInternal->GetDocument(getter_AddRefs(focusedDOMDocument));
+      focusedDOMDocument->QueryInterface(NS_GET_IID(nsIDOMNode), (void**)&focusedNode);
+    }
+  }
+  return focusedNode;
+}
diff --git a/mozilla/accessible/src/base/nsAccessNode.h b/mozilla/accessible/src/base/nsAccessNode.h
index 3a373a7f35a..a672277dd8c 100755
--- a/mozilla/accessible/src/base/nsAccessNode.h
+++ b/mozilla/accessible/src/base/nsAccessNode.h
@@ -149,6 +149,7 @@ class nsAccessNode: public nsIAccessNode, public nsPIAccessNode
 
     static nsIDOMNode *gLastFocusedNode;
     static nsIAccessibilityService* GetAccService();
+    already_AddRefed<nsIDOMNode> GetCurrentFocus();
 
 protected:
     nsresult MakeAccessNode(nsIDOMNode *aNode, nsIAccessNode **aAccessNode);
diff --git a/mozilla/accessible/src/base/nsAccessibilityAtomList.h b/mozilla/accessible/src/base/nsAccessibilityAtomList.h
index ceaa717f70c..2368be096ca 100755
--- a/mozilla/accessible/src/base/nsAccessibilityAtomList.h
+++ b/mozilla/accessible/src/base/nsAccessibilityAtomList.h
@@ -164,6 +164,7 @@ ACCESSIBILITY_ATOM(type, "type")
 ACCESSIBILITY_ATOM(value, "value")
 
   // ARIA (DHTML accessibility) attributes
+ACCESSIBILITY_ATOM(activedescendant, "activedescendant")
 ACCESSIBILITY_ATOM(checked, "checked")
 ACCESSIBILITY_ATOM(droppable, "droppable")
 ACCESSIBILITY_ATOM(expanded, "expanded")
diff --git a/mozilla/accessible/src/base/nsDocAccessible.cpp b/mozilla/accessible/src/base/nsDocAccessible.cpp
index f53dd2c730c..7300b7fa124 100644
--- a/mozilla/accessible/src/base/nsDocAccessible.cpp
+++ b/mozilla/accessible/src/base/nsDocAccessible.cpp
@@ -36,7 +36,7 @@
  *
  * ***** END LICENSE BLOCK ***** */
 
-#include "nsDocAccessible.h"
+#include "nsRootAccessible.h"
 #include "nsAccessibilityAtoms.h"
 #include "nsAccessibleEventData.h"
 #include "nsIAccessibilityService.h"
@@ -945,20 +945,35 @@ nsDocAccessible::AttributeChanged(nsIDocument *aDocument, nsIContent* aContent,
     }
   }
   else if (aNameSpaceID == kNameSpaceID_WAIProperties) {
-    // DHTML accessibility attributes
-    if (!HasRoleAttribute(aContent)) {
-      // We don't care about DHTML state changes unless there is
-      // a DHTML role set for the element
+    // ARIA attributes
+    if (aAttribute == nsAccessibilityAtoms::disabled ||
+        aAttribute == nsAccessibilityAtoms::required ||
+        aAttribute == nsAccessibilityAtoms::invalid) {
+      // Universal boolean properties that don't require a role
+      eventType = nsIAccessibleEvent::EVENT_STATE_CHANGE;
+    }
+    else if (aAttribute == nsAccessibilityAtoms::activedescendant) {
+      // The activedescendant universal property redirects accessible focus events
+      // to the element with the id that activedescendant points to
+      nsCOMPtr<nsIDOMNode> currentFocus = GetCurrentFocus();
+      if (SameCOMIdentity(currentFocus, aContent)) {
+        nsRefPtr<nsRootAccessible> rootAcc = GetRootAccessible();
+        if (rootAcc) {
+          rootAcc->FireAccessibleFocusEvent(nsnull, currentFocus, nsnull, PR_TRUE);
+        }
+      }
+      return;
+    }
+    else if (!HasRoleAttribute(aContent)) {
+      // We don't care about these other ARIA attribute changes unless there is
+      // an ARIA role set for the element
+      // XXX we should check the role map to see if the changed
+      // property is relevant for that particular role
       return;
     }
     if (aAttribute == nsAccessibilityAtoms::checked ||
-        aAttribute == nsAccessibilityAtoms::expanded) {
-      eventType = nsIAccessibleEvent::EVENT_STATE_CHANGE;
-    }
-    else if (aAttribute == nsAccessibilityAtoms::readonly ||
-             aAttribute == nsAccessibilityAtoms::disabled ||
-             aAttribute == nsAccessibilityAtoms::required ||
-             aAttribute == nsAccessibilityAtoms::invalid) {
+        aAttribute == nsAccessibilityAtoms::expanded || 
+        aAttribute == nsAccessibilityAtoms::readonly) {
       eventType = nsIAccessibleEvent::EVENT_STATE_CHANGE;
     }
     else if (aAttribute == nsAccessibilityAtoms::valuenow) {
diff --git a/mozilla/accessible/src/base/nsRootAccessible.cpp b/mozilla/accessible/src/base/nsRootAccessible.cpp
index 28179b44868..c86628b675b 100644
--- a/mozilla/accessible/src/base/nsRootAccessible.cpp
+++ b/mozilla/accessible/src/base/nsRootAccessible.cpp
@@ -443,8 +443,6 @@ void nsRootAccessible::FireAccessibleFocusEvent(nsIAccessible *aAccessible,
                                                 nsIDOMEvent *aFocusEvent,
                                                 PRBool aForceEvent)
 {
-  NS_ASSERTION(aAccessible, "Attempted to fire focus event for no accessible");
-
   if (mCaretAccessible) {
     nsCOMPtr<nsIDOMNSEvent> nsevent(do_QueryInterface(aFocusEvent));
     if (nsevent) {
@@ -465,23 +463,51 @@ void nsRootAccessible::FireAccessibleFocusEvent(nsIAccessible *aAccessible,
     }
   }
 
+  // Check for aaa:activedescendant, which changes which element has focus
+  nsCOMPtr<nsIDOMNode> finalFocusNode = aNode;
+  nsCOMPtr<nsIAccessible> finalFocusAccessible = aAccessible;
+  nsCOMPtr<nsIContent> finalFocusContent  = do_QueryInterface(aNode);
+  if (finalFocusContent) {
+    nsAutoString id;
+    if (finalFocusContent->GetAttr(kNameSpaceID_WAIProperties, nsAccessibilityAtoms::activedescendant, id)) {
+      nsCOMPtr<nsIDOMDocument> domDoc;
+      aNode->GetOwnerDocument(getter_AddRefs(domDoc));
+      if (!domDoc) {
+        return;
+      }
+      nsCOMPtr<nsIDOMElement> relatedEl;
+      domDoc->GetElementById(id, getter_AddRefs(relatedEl));
+      finalFocusContent = do_QueryInterface(relatedEl);
+      if (!finalFocusContent) {
+        return;
+      }
+      GetAccService()->GetAccessibleFor(finalFocusNode, getter_AddRefs(finalFocusAccessible));      
+      // XXX Deal with case where finalFocusNode is not in parent chain of original true focus (aNode).
+      // We need direction from ARIA spec -- should we just return because it's not valid?
+      // Or should we put focus on the original container node?
+    }
+  }
+
   // Fire focus only if it changes, but always fire focus events when aForceEvent == PR_TRUE
-  if (gLastFocusedNode == aNode && !aForceEvent) {
+  if (gLastFocusedNode == finalFocusNode && !aForceEvent) {
     return;
   }
 
   nsCOMPtr<nsPIAccessible> privateAccessible =
-    do_QueryInterface(aAccessible);
+    do_QueryInterface(finalFocusAccessible);
   NS_ASSERTION(privateAccessible , "No nsPIAccessible for nsIAccessible");
+  if (!privateAccessible) {
+    return;
+  }
 
   // Use focus events on DHTML menuitems to indicate when to fire menustart and menuend
   // Special dynamic content handling
   PRUint32 role = ROLE_NOTHING;
-  aAccessible->GetFinalRole(&role);
+  finalFocusAccessible->GetFinalRole(&role);
   if (role == ROLE_MENUITEM) {
     if (!mIsInDHTMLMenu) {  // Entering menus
       PRUint32 naturalRole; // The natural role is the role that this type of element normally has
-      aAccessible->GetRole(&naturalRole);
+      finalFocusAccessible->GetRole(&naturalRole);
       if (role != naturalRole) { // Must be a DHTML menuitem
          FireToolkitEvent(nsIAccessibleEvent::EVENT_MENUSTART, this, nsnull);
          mIsInDHTMLMenu = ROLE_MENUITEM;
@@ -494,41 +520,16 @@ void nsRootAccessible::FireAccessibleFocusEvent(nsIAccessible *aAccessible,
   }
 
   NS_IF_RELEASE(gLastFocusedNode);
-  gLastFocusedNode = aNode;
+  gLastFocusedNode = finalFocusNode;
   NS_IF_ADDREF(gLastFocusedNode);
 
   privateAccessible->FireToolkitEvent(nsIAccessibleEvent::EVENT_FOCUS,
-                                      aAccessible, nsnull);
+                                      finalFocusAccessible, nsnull);
 }
 
 void nsRootAccessible::FireCurrentFocusEvent()
 {
-  nsCOMPtr<nsIDOMWindow> domWin;
-  GetWindow(getter_AddRefs(domWin));
-  nsCOMPtr<nsPIDOMWindow> privateDOMWindow(do_QueryInterface(domWin));
-  if (!privateDOMWindow) {
-    return;
-  }
-  nsIFocusController *focusController = privateDOMWindow->GetRootFocusController();
-  if (!focusController) {
-    return;
-  }
-  nsCOMPtr<nsIDOMElement> focusedElement;
-  focusController->GetFocusedElement(getter_AddRefs(focusedElement));
-  nsCOMPtr<nsIDOMNode> focusedNode(do_QueryInterface(focusedElement));
-  if (!focusedNode) {
-    // Document itself may have focus
-    nsCOMPtr<nsIDOMWindowInternal> focusedWinInternal;
-    focusController->GetFocusedWindow(getter_AddRefs(focusedWinInternal));
-    if (focusedWinInternal) {
-      nsCOMPtr<nsIDOMDocument> focusedDOMDocument;
-      focusedWinInternal->GetDocument(getter_AddRefs(focusedDOMDocument));
-      focusedNode = do_QueryInterface(focusedDOMDocument);
-    }
-    if (!focusedNode) {
-      return;  // Could not get a focused document either
-    }
-  }
+  nsCOMPtr<nsIDOMNode> focusedNode = GetCurrentFocus();
 
   // Simulate a focus event so that we can reuse code that fires focus for container children like treeitems
   nsCOMPtr<nsIDOMDocumentEvent> docEvent = do_QueryInterface(mDocument);
diff --git a/mozilla/accessible/src/base/nsRootAccessible.h b/mozilla/accessible/src/base/nsRootAccessible.h
index 50986a1c8ed..c6ac1406f70 100644
--- a/mozilla/accessible/src/base/nsRootAccessible.h
+++ b/mozilla/accessible/src/base/nsRootAccessible.h
@@ -91,6 +91,11 @@ class nsRootAccessible : public nsDocAccessibleWrap,
     
     NS_DECLARE_STATIC_IID_ACCESSOR(NS_ROOTACCESSIBLE_IMPL_CID)
 
+    void FireAccessibleFocusEvent(nsIAccessible *focusAccessible,
+                                  nsIDOMNode *focusNode,
+                                  nsIDOMEvent *aFocusEvent,
+                                  PRBool aForceEvent = PR_FALSE);
+
   private:
     nsCOMPtr<nsITimer> mFireFocusTimer;
     static void FireFocusCallback(nsITimer *aTimer, void *aClosure);
@@ -102,10 +107,6 @@ class nsRootAccessible : public nsDocAccessibleWrap,
                                            nsIDOMNode* aTargetNode);
     static void GetTargetNode(nsIDOMEvent *aEvent, nsIDOMNode **aTargetNode);
     void TryFireEarlyLoadEvent(nsIDOMNode *aDocNode);
-    void FireAccessibleFocusEvent(nsIAccessible *focusAccessible,
-                                  nsIDOMNode *focusNode,
-                                  nsIDOMEvent *aFocusEvent,
-                                  PRBool aForceEvent = PR_FALSE);
     void FireCurrentFocusEvent();
     void GetChromeEventHandler(nsIDOMEventTarget **aChromeTarget);
 #ifdef MOZ_XUL